It took me many years to have sustained eye contact with T. At first, I sort of pushed myself to do it, almost as a way of challenging T. When she didn't back down, it became easier to look her in the eye, so now it happens more frequently, although not as often as it should. But when we are talking about a good thing that happened to me, I can almost always sustain eye contact.
When I feel angry, scared, ashamed, embarrassed or humiliated ( most of this is transference, I think), then I can't look at her. When I look away she often asks, "What just happened?"